Construction Of Photocatalyst With Visible Light Response And Long Afterglow Characteristics And Its Application In Photocatalytic Water-splitting

How to solve the problem of depletion of fossil energy and environmental pollution is one of the biggest technological challenges faced by scientific and technological personnel.Solar energy reserves are almost infinite clean energy.Hydrogen is a clean energy with high energy density.Using photocatalyst to decompose water into hydrogen and oxygen is an effective way to clean and utilize solar energy.However,most semiconductor materials respond only to ultraviolet light,but ultraviolet light accounts for only about 5% of solar energy,while visible light,which accounts for 43% of sunlight,is not used.In addition,the short lifetime of photogenerated carriers is a key factor affecting the improvement of photocatalytic efficiency.Therefore,research and development of photocatalysts with visible light response and increasing their photo-generated carrier lifetime are important for the improvement of photocatalytic efficiency.This article is divided into five chapters:The first chapter is the introduction,and summarizes the research progress of photocatalytic decomposition of water hydrogen production in recent years,and focuses on the research progress of Mo S2,WO3,Cu3 P and other materials.In the second chapter,we prepared a micron-sized nitrogen-doped three-way carbon tube(TNCT)by calcination method.Then,the Mo S2 nanosheet was loaded onto TNCT by simple hydrothermal method,and finally the TNCT@Mo S2 micron tube was successfully synthesized.The photocatalytic hydrogen production performance of the material was systematically investigated and its photocatalytic reaction mechanism was discussed.Compared with Mo S2 and TNCT alone,TNCT@Mo S2 exhibits excellent photocatalytic performance and its hydrogen evolution rate is greatly improved.This is mainly due to the improved efficiency of photo-generated carrier separation.In the third chapter,we designed an all-solid-Z photocatalytic system that responds to visible light to promote the spatial separation of WO3 photogenerated charge.We synthesized different loadings of Cu3P@WO3 catalyst by impregnationmethod to test the performance of photocatalytic hydrogen production under full light.It was found that the hydrogen production of 10% Cu3P@WO3 was significantly higher than that of WO3 and Cu3 P alone.This is mainly due to the fact that the electrons on the valence band of WO3 are transferred to the conduction band of Cu3 P to bind to their holes,forming a Z-type photocatalytic system to promote the separation of electrons and holes.In the fourth chapter,based on the preliminary work of this group,Sr2 Mg Si2O7:Eu2+,Ce3+,Tb3+ were synthesized by sol-gel method,which produced hydrogen production and oxygen production under full light,and continued hydrogen production and oxygen production in dark environment..This is attributed to the formation of a special electron transfer pathway between Ce3+ and Eu2+,and electron conjugation between Eu2+ and Tb3+,and Ce3+ has an energy transfer effect on Tb3+and Eu2+,thereby improving photocatalytic performance.The fifth chapter summarizes and forecasts the work of this paper.